Method Overloading

1. BY: HUMA SAMIN
Method Overloading

2. Method Overloading
In Java it is possible to define two or more methods
within the same class that share the same name, as
long as their parameter declarations are different.
The methods are called overloaded methods.
The process is called method overloading.
When an overloaded method is invoked, Java uses
the type and/or number of arguments t0 determine
which version of the overloaded method to actually
call.

3. Example
public Class OverLoadDemo
{
void test( )
{
System.out.println(“No parameters”);
}
void test(int a)
{
System.out.println(“a: ”+a);
}
void test( int a, int b)
{
System.out.println(“a: ”+ a+ “b: ”+ b);
}
double test(double a)
{
System.out.println(“a: ”+ a);
return a*a;
}
}

4. Example cont..
public class OverLoadDemoDriver
{
public static void main(String args[])
{
OverLoadDemo o=new OverLoadDemo( );
o.test( );
o.test(10);
o.test(10,20);
double d;
d=o.test( 10.7);
}
}
Note: 1. Method overloading doesn’t depend on the return type.
2. Automatic type casting is allowed while calling methods.

5. Method Overloading
Method overloading implements the concept of
polymorphism in java.
“Poly” means many and “morph” means forms.

6. Constructor Overloading
Just like methods constructors can be overloaded.
One class can have more than one constructors
defined.
All the rules of constructor overloading are the same
as that of method overloading.

7. Example
public class Student
{
//data members or instance variables
private int rollNo;
public int semester;
//behavior or methods are kept public
// Overloaded Constructors
public Student( )
{
rollNo=10;
semester=2;
}
public Student(int r)
{
rollNo=r;
semester=2;
}
public Student(int r, int s)
{
rollNo=r;
semester=s;
}
public void displayValues( )
{
System.out.println(rollNo);
System.out.println(semester);
}
}

8. Example cont..
public class StudentDriver
{
public static void main(String args[ ])
{
Student s, s1,s2;
s=new Student( );
s1=new Student(23);
s2=new Student(45,3);
s.displayValues();
s1.displayValues();
s2.displayValues();
}
}